Tire And Tire Track Evidence: Recovery And Forensic Examination Book

Preface     xix
Acknowledgments     xxi
About the Author     xxiii
General Tire Information     1
From the Wheel to the Tire     1
The Pneumatic Tire     3
Tire Footprint or Contact Patch     3
How a Tire Carries the Load     4
Tire Evolution     6
Original Equipment Manufacturer Tires (OEM)     9
Replacement Tires     10
Tread Design     10
Information on Sidewalls     10
Tire Brand     12
Manufacturer's Line of Tire     12
Tire Size Designation     12
Rim Diameter     13
Section Width     13
Aspect Ratio
Load Index     13
Speed Ratings     13
Tire Pressure     15
Department of Transportation (DOT) Number     18
Mold Number     19
Economic Commission for Europe (ECE) Symbols     20
Uniform Tire Quality Grading     20
Wheels and Rims     20
Track Evidence     23
Track Evidence     23
How Vehicles Track     23
Tread Width     27
Track Width     29
Turning Diameter     31
Wheelbase     33
Rolling Circumference     35
Making Measurements of the Suspect Vehicle     37
Aftermarket Wheels and Tires     37
Other Track Evidence     39
Documenting and Recovering Tire Impression Evidence     45
The Crime Scene     45
Putting Tire Impression Recovery in Perspective     48
Detail Retained in Impressions     49
Recovery of Impression Evidence     50
Original Tire Evidence     52
Photographing Tire Evidence at the Crime Scene     52
Film versus Digital Cameras     52
General Crime Scene Photographs     53
Examination Quality Photographs     58
Casting Three-Dimensional Impressions     67
Dental Stone Materials     69
Determining the Powder-to-Water Ratio     70
Preparing the Impression for Casting     71
Mixing     72
Pouring     73
Labeling the Cast     74
Recovering the Cast     75
Drying and Cleaning the Cast     76
Tire Impressions in Snow     77
Dry-Casting Snow Impressions     79
Snow Print Wax and Snow Impression Wax     82
Casting Snow Impressions with Sulfur     83
Lifting Tire Impressions     87
Contusions     88
Known Exemplars of Tires for Elimination and Examination     93
General Information     93
Documenting Tires From Elimination Vehicles     93
Photographs of the Tread Design     94
White Adhesive Lift of Tire design     95
Identicator Inkless Method and Materials     97
Other Methods     98
Known Exemplar Impressions of a Suspect Vehicle     98
General Instructions     99
General Materials     100
Methods     102
Inked Impressions on Clear Wet Media Film     102
Inked Impressions on White Board     110
Powdered Impressions on Clear Wet Media Film     110
Powdered Impressions on White Board     114
Treadprint     114
Additional Techniques     116
Dual Tire Assemblies     117
Key Points     118
Tire Manufacturing     119
Designing a Tire     119
Tire Mold Types     120
Mold-Making Methods     124
Cast Molds      125
Engraved Molds     127
Mold Finishing     128
Ventless Molds     128
Tire Manufacturing     130
Tire Components     130
Building the Tire     133
Molding and Curing     135
Final Finishing and Quality Control     137
Retreaded Tires     139
Retreading Defined     139
How Tires Are Retreaded     139
Tire Inspection     140
Pre-Cure Method     141
Pre-Cure Tread Design Stock     147
Ring Tread Process     148
Mold Cure Method     148
Segmented Mold Cure     149
Solid Tread Ring Mold Cure     149
Bead-to-Bead Mold Cure     149
Retread DOTR Number     149
Determining Whether a Tire Is Retreaded     152
Splice     152
Wicking Cloth     152
Irregular Edge Bond Filling     152
Lettering on Edges of Tread Stock     152
Variations in Coloring     152
Correlation of Tread Design and Sidewall Information     153
Close Examination of the Interface at the Shoulder     154
Mold Cured Tires     154
Forensic Significance of Crime Scene Impressions Made by Retread Tires     154
Regrooving     155
Tread Design and Dimension     157
Tire Parameters Affect Design     157
Tread Design     159
Tread Design Terminology     159
Tread Design Categories     163
Non-Directional Symmetrical Tread Design     163
Directional Tread Design     164
Asymmetric Tread Design     166
Other Categories or Types of Tread Design     166
Rib and Center Rib Tires     166
Block Design     167
All-Terrain and Off-Road Tires     167
Motorcycle Tires     167
Snow Tires     169
High-Performance Tires     169
Agriculture and Construction Tires     170
All-Season Tires     171
Spare Tires     171
Self-Sealing Tires     171
Run Flat Tires or Self-Supporting Tires     172
Implement Tires     172
Bicycle Tires     172
Tread Dimension     172
Accuracy of Tread Dimensions in Impressions     172
Factors in Dimensional Evaluation     173
Inadequate Known Exemplars      173
Tires with Tread Blocks of One Size (No Noise Treatment)     173
Impressions with Limited Size or Detail     173
Changes in Tire Inflation     173
Improperly Photographed Impressions     174
Saturated and Spongy Substrates     174
Footprint or Contact Patch     174
Deflection     175
Forensic Significance of Deflection     176
Noise Treatment     176
Introduction to Noise Treatment and Pitch Length     176
Evolution of Noise Treatment     178
Modern Noise Treatment Differs on Each Tire Side     181
Tires without Noise Treatment     183
Tread Wear Indicators     184
Using Tread Wear Indicators and Noise Treatment Together     185
Noise Treatment and Tread Wear Indicator Combination Possibilities     187
Vehicles Tires of Multiple Tread Designs     190
Vehicle Tires of Varying Sizes     192
Tire Wear     193
Use of Wear in Forensic Examinations     193
Wear Terminology     193
Causes of Tire Wear     194
Characteristics of Tire Wear     197
Wear Characteristics Retained in Two-Dimensional Impressions     197
Wear Characteristics Retained in Three-Dimensional Impressions     197
Sipe Characteristics Change with Wear     199
Groove Depth and Taper     200
Tread Wear Indicators     202
Tread Depth Gauges     204
Potential Unreliability of Tread Depth Measurements     204
Forensic Significance of Wear     207
Individual Characteristics     209
Individualization     209
The Individualization of a Tire     209
Examples of Individual Characteristics of Tires     210
Cuts and Scratches     210
Tears and Rips     211
Stone Holds     212
Nails     213
Plugs and Patches     213
Excessive Erosion of Tread     214
Recording Individual Characteristics in a Substrate     214
Weight of Individual Characteristics     215
Changes in Individual Characteristics with Additional Wear     220
Examination Methodology and Procedure for Comparison of Tire Impressions     223
Structured Examination Procedure     223
Note Taking     224
Preparation for Examination     226
The Process of Examining Tire Impressions     228
Tread Design and Dimension      228
Using the Inked Impressions to Learn about Tire Design and Dimensions     230
Confirming Correspondence in Tread Design and Dimension     238
Examiner Experience     238
Using Tread Wear Indicators     238
Deflection Variables     238
Inflation Differences     240
Soil Movement and Condition     240
Possible Results Regarding Tread Design and Dimension     241
Different Tread Design     241
Similar or Same General Tread Design     242
Tread Design and Dimension Correspond     243
Continuing the Examination Process     243
Wear Characteristics     245
Tread Depth     247
Forensic Significance of Wear     247
Individual Characteristics     248
Clarity of Characteristics     249
Weight or Value of Characteristics     251
Absence of Individual Characteristics     252
Partial Width Impressions     252
Reporting Results     252
Scientific Method     254
Additional Comments     255
Presenting Tire Evidence in Court     257
Preparation     257
Demonstration Aids      257
Photographs     258
PowerPoint Presentations     258
Adobe Photoshop     259
Visual Presenters     260
Screens versus TV Monitors     260
Planning Ahead     261
Pre-Trial Meeting with Attorney     261
Testifying to Your Conclusions     261
Resources and Databases     263
Resources     263
Tire Guides, Inc.     263
Tread Design Guide     263
Tread Assistant CD-ROM (Computerized Tread Design Guide)     270
Who Makes It and Where Tire Directory     270
OEM Tire Size Guide     271
Who Retreads Tires     276
Tire Guide     276
Tire Business     279
Tire Retread Information Bureau     280
JATO DYNAMICS     280
Michigan and RCMP Track Databases     282
European Databases     283
SICAR TreadMate     283
Books     285
SWGTREAD     286
Case Studies     287
Kunz Family Homicides     287
Mary Lou Arruda Homicide     293
Hit-and-Run Civil Case     298
The Tire Evidence in the Oklahoma City Bombing Case      305
Glossary     323
Bibliography     329
Index     333